US 6,396,859 B1 · Chiral twist laser and filter apparatus and method

Abstract

A defect causing a localized state is induced in a chiral structure composed of multiple chiral elements by twisting one element of the chiral structure with respect to the other elements along a common longitudinal axis such that directors of the element molecular layers that are in contact with one another are disposed at a particular “twist” angle therebetween, the twist angle being greater than a shift angle between directors of consecutive layers. The chiral twist structure may be utilized in a variety of applications such as filters, lasers and detectors. The defect caused by the twist may be made tunable by providing a tuning device for ly rotating one or more of the chiral elements with respect to one another to vary the twist angle and thus vary the position of the induced defect within a photonic stop band. Tunable defects may be advantageously utilized to construct wavelength tunable chiral filters, detectors and lasers.

Claims60

Dependent claims

A chiral structure comprising:

a first chiral element having a first plurality of molecular layers, each of said first plurality of layers having a unique first director generally representative of an orientation of molecules in said layer each pair of said plural first directors having a shift angle therebetween, and a first contact layer having a first contact director;
and
a second chiral element having a second plurality of molecular layers, each of said second plurality of layers having a unique second director generally representative of an orientation of molecules in said layer, each pair of said plural second directors having a shift angle therebetween, and a second contact layer having a second contact director, wherein said first and second chiral elements are positioned sequentially to one another such that said first contact layer is in substantial contact with said second contact layer, wherein said first and said second chiral elements are twisted with respect to one another about a common axis perpendicular to said first and second plural molecular layers at a twist angle to cause a twist defect within the chiral structure, thereby inducing a localized photonic state in a photonic stop band of the chiral structure at a wavelength proportional to a magnitude of said twist angle.

A chiral laser, comprising:

a first chiral element of a predefined length having a first plurality of molecular layers, each of said first plurality of layers having a unique first director generally representative of an orientation of molecules in said layer, each pair of said plural first directors having a shift angle therebetween, and a first contact layer having a first contact director;
a second chiral element of said predefined length having a second plurality of molecular layers, each of said second plurality of layers having a unique second director generally representative of an orientation of molecules in said layer each pair of said plural second directors having a shift angle therebetween, and a second contact layer having a second contact director,
a excitable light-emitting element disposed between said first contact layer and said second contact layer, said first and second chiral elements being positioned sequentially to one another, such that said first and said second chiral elements are twisted with respect to one another about a common axis perpendicular to said first and second plural molecular layers at a twist angle, said twist causing a defect within the chiral laser, said defect inducing a localized photonic state in a photonic stop band of the chiral structure at a wavelength proportional to a magnitude of said twist angle;
and
an excitation means, applied to said light-emitting element, for causing said light-emitting element to emit electromagnetic radiation, wherein:
when said predefined length is substantially below a predefined threshold, substantially right-circularly polarized lasing occurs at a lasing wavelength corresponding to a position of said localized photonic state induced by said defect, said photonic state being centered at a wavelength proportional to a magnitude of said twist angle,
when said predefined length is substantially equal to said predefined threshold, substantially normal polarized lasing occurs at a lasing wavelength corresponding to said position of said localized photonic state induced by said defect, said photonic state being centered at a wavelength proportional to a magnitude of said twist angle, and
when said predefined length is substantially greater than said predefined threshold, substantially left-circularly polarized lasing occurs at a lasing wavelength corresponding to said position of said localized photonic state induced by said defect, said photonic state being centered at a wavelength proportional to a magnitude of said twist angle.

5 more elements

A chiral laser, comprising:

a first chiral element of a predefined length having a first plurality of molecular layers, each of said first plurality of layers having a unique first director generally representative of an orientation of molecules in said layer, each pair of said plural first directors having a shift angle therebetween, and a first contact layer having a first contact director;
a second chiral element of said predefined length having a second plurality of molecular layers, each of said second plurality of layers having a unique second director generally representative of an orientation of molecules in said layer, each pair of said plural second directors having a shift angle therebetween, and a second contact layer having a second contact director, wherein said first and second chiral elements are doped with an active excitable light-emitting material and positioned sequentially to one another such that:
(a) said first contact layer is in substantial contact with said second contact layer and (b) said first and said second chiral elements are twisted with respect to one another about a common axis perpendicular to said first and second plural molecular layers at a twist angle, said twist causing a defect within the chiral laser;
and
an excitation means, applied to said first and second chiral elements, for causing said light-emitting materials doped therein to emit electromagnetic radiation, wherein:
when said predefined length is substantially below a predefined threshold, substantially right-circularly polarized lasing occurs at a lasing wavelength corresponding to a position of said localized photonic state induced by said defect, said photonic state being centered at a wavelength proportional to a magnitude of said twist angle,
when said predefined length is substantially equal to said predefined threshold, substantially normal polarized lasing occurs at a lasing wavelength corresponding to said position of said localized photonic state induced by said defect, said photonic state being centered at a wavelength proportional to a magnitude of said twist angle, and
when said predefined length is substantially greater than said predefined threshold, substantially left-circularly polarized lasing occurs at a lasing wavelength corresponding to said position of said localized photonic state induced by said defect, said photonic state being centered at a wavelength proportional to a magnitude of said twist angle.

5 more elements

A method of generating a defect in an chiral structure comprising the steps of:

(a) providing a first chiral element having a first plurality of molecular layers, each of said first plurality of layers having a unique first director generally representative of an orientation of molecules in said layer, each pair of said plural first directors having a shift angle therebetween, and a first contact layer having a first contact director;
and
(b) providing a second chiral element having a second plurality of molecular layers, each of said second plurality of layers having a unique second director generally representative of an orientation of molecules in said layer, each pair of said plural second directors having a shift angle therebetween, and a second contact layer having a second contact director,
(c) positioning said first and second chiral elements sequentially to one another such that said first contact layer is in substantial contact with said second contact layer;
and
(d) twisting said first and said second chiral elements with respect to one another about a common axis perpendicular to said first and second plural molecular layers at a twist angle, to cause a twist defect within the chiral structure formed by said first and second chiral elements, thereby inducing a localized photonic state in a photonic stop band of the chiral structure at a wavelength proportional to a magnitude of said twist angle.

3 more elements

A method of lasing utilizing a chiral structure, comprising the steps of:

(a) providing a first chiral element of a predefined length having a first plurality of molecular layers, each of said first plurality of layers having a unique first director generally representative of an orientation of molecules in said layer, each pair of said plural first directors having a shift angle therebetween, and a first contact layer having a first contact director;
(b) providing a second chiral element of said predefined length having a second plurality of molecular layers, each of said second plurality of layers having a unique second director generally representative of an orientation of molecules in said layer each pair of said plural second directors having a shift angle therebetween, and a second contact layer having a second contact director,
(c) providing a excitable light-emitting element between said first contact layer and said second contact layer,
(d) twisting said first and said second chiral elements with respect to one another about a common axis perpendicular to said first and second plural molecular layers at a twist angle, said twist causing a defect within the chiral laser, said defect inducing a localized photonic state in a photonic stop band of within a chiral structure formed by said first and second chiral elements at a wavelength proportional to a magnitude of said twist angle;
(e) applying excitation to said light-emitting element to cause said light-emitting element to emit electromagnetic radiation;
(f) when said predefined length is substantially below a predefined threshold, lasing with substantially right-circularly polarized light at a lasing wavelength corresponding to a position of said localized photonic state induced by said defect, said photonic state being centered at a wavelength proportional to a magnitude of said twist angle;
(g) when said predefined length is substantially equal to said predefined threshold, lasing with substantially normal polarized light at a lasing wavelength corresponding to said position of said localized photonic state induced by said defect, said photonic state being centered at a wavelength proportional to a magnitude of said twist angle;
and
(h) when said predefined length is substantially greater than said predefined threshold, lasing with substantially left-circularly polarized light at a lasing wavelength corresponding to said position of said localized photonic state induced by said defect, said photonic state being centered at a wavelength proportional to a magnitude of said twist angle.

6 more elements

A method of lasing utilizing a chiral structure, comprising the steps of:

(a) providing a first chiral element of a predefined length doped with an active excitable light-emitting material and having a first plurality of molecular layers, each of said first plurality of layers having a unique first director generally representative of an orientation of molecules in said layer, each pair of said plural first directors having a shift angle therebetween, and a first contact layer having a first contact director;
(b) providing a second chiral element of said predefined length doped with an active excitable light-emitting material and having a second plurality of molecular layers, each of said second plurality of layers having a unique second director generally representative of an orientation of molecules in said layer each pair of said plural second directors having a shift angle therebetween, and a second contact layer having a second contact director,
(c) twisting said first and said second chiral elements with respect to one another about a common axis perpendicular to said first and second plural molecular layers at a twist angle, said twist causing a defect within the chiral laser, said defect inducing a localized photonic state in a photonic stop band of within a chiral structure formed by said first and second chiral elements at a wavelength proportional to a magnitude of said twist angle;
(d) applying excitation to said first and said second chiral elements to cause said light-emitting materials doped therein to emit electromagnetic radiation;
(e) when said predefined length is substantially below a predefined threshold, lasing with substantially right-circularly polarized light at a lasing wavelength corresponding to a position of said localized photonic state induced by said defect, said photonic state being centered at a wavelength proportional to a magnitude of said twist angle;
(f) when said predefined length is substantially equal to said predefined threshold, lasing with substantially normal polarized light at a lasing wavelength corresponding to said position of said localized photonic state induced by said defect, said photonic state being centered at a wavelength proportional to a magnitude of said twist angle;
and
(g) when said predefined length is substantially greater than said predefined threshold, lasing with substantially left-circularly polarized light at a lasing wavelength corresponding to said position of said localized photonic state induced by said defect, said photonic state being centered at a wavelength proportional to a magnitude of said twist angle.

5 more elements

Dependencies are inferred from the claim text.

Chiral twist laser and filter apparatus and method

Life of this patent

Chiral twist laser and filter apparatus and method

Life of this patent

Abstract

Claims60